/// <summary>
/// Removes castling possibility if needed.
/// </summary>
/// <param name="bitboard">The bitboard.</param>
private void CalculateCastling(Bitboard bitboard)
{
switch (Piece)
{
case PieceType.King:
{
var shortCastlingIndex = FastArray.GetCastlingIndex(Color, CastlingType.Short);
var longCastlingIndex = FastArray.GetCastlingIndex(Color, CastlingType.Long);
IncrementalZobrist.RemoveCastlingPossibility(Color, CastlingType.Short, bitboard);
IncrementalZobrist.RemoveCastlingPossibility(Color, CastlingType.Long, bitboard);
bitboard.CastlingPossibility[shortCastlingIndex] = false;
bitboard.CastlingPossibility[longCastlingIndex] = false;
break;
}
case PieceType.Rook:
{
if (From == new Position(1, 1) || From == new Position(1, 8))
{
IncrementalZobrist.RemoveCastlingPossibility(Color, CastlingType.Long, bitboard);
bitboard.CastlingPossibility[FastArray.GetCastlingIndex(Color, CastlingType.Long)] = false;
}
else if (From == new Position(8, 1) || From == new Position(8, 8))
{
IncrementalZobrist.RemoveCastlingPossibility(Color, CastlingType.Short, bitboard);
bitboard.CastlingPossibility[FastArray.GetCastlingIndex(Color, CastlingType.Short)] = false;
}
break;
}
}
}
/// <summary>
/// Removes castling possibility Zobrist hash.
/// </summary>
/// <param name="color">The piece color.</param>
/// <param name="castlingType">The castling type.</param>
/// <param name="bitboard">The bitboard.</param>
public static void RemoveCastlingPossibility(Color color, CastlingType castlingType, Bitboard bitboard)
{
var castlingIndex = FastArray.GetCastlingIndex(color, castlingType);
if (bitboard.CastlingPossibility[castlingIndex])
{
bitboard.Hash ^= ZobristContainer.Castling[castlingIndex];
}
}
/// <summary>
/// Removes castling possibility from the specified bitboard.
/// </summary>
/// <param name="bitboard">The bitboard.</param>
private void RemoveCastlingPossibility(Bitboard bitboard)
{
IncrementalZobrist.RemoveCastlingPossibility(Color, CastlingType.Short, bitboard);
IncrementalZobrist.RemoveCastlingPossibility(Color, CastlingType.Long, bitboard);
bitboard.CastlingPossibility[FastArray.GetCastlingIndex(Color, CastlingType.Short)] = false;
bitboard.CastlingPossibility[FastArray.GetCastlingIndex(Color, CastlingType.Long)] = false;
IncrementalCastling.SetCastlingDone(bitboard, Color);
bitboard.CastlingDone[(int)Color] = true;
}
/// <summary>
/// Checks if castling with the specified type is possible.
/// </summary>
/// <param name="type">The castling type.</param>
/// <param name="opt">The generator parameters.</param>
/// <returns>True if castling is possible, otherwise false.</returns>
private static bool IsCastlingPossible(CastlingType type, GeneratorParameters opt)
{
return(opt.Bitboard.CastlingPossibility[FastArray.GetCastlingIndex(opt.FriendlyColor, type)]);
}